Diverting Blood Clots to Prevent Strokes

The Diverter device is designed to reduce the occurrence of strokes by sending clots and thrombotic particles away from the brain into a non-hazardous location.An Israeli-developed stent-like device developed to divert blood clots which cause embolic strokes has been implanted into a human for the first time.

As a result, MindGuard Medical Devices is about to start clinical trials on their device called the Diverter, which has already been proven in animal tests to divert the blood clots that cause a stroke away from the sensitive brain area to other safe areas.

Stroke is the third leading cause of death in the United States and the leading cause of serious, long-term disability. Each year, approximately 700,000 U.S. residents experience a new or recurrent stroke; an estimated 500,000 U.S residents will have their first stroke. Similarly, In Europe and in other countries, stroke also constitutes a major cause of death and disability.

The human implantation was performed at the beginning of October by Prof. Horst Sievert, at the Cardio Vascular Center Frankfurt, Sankt Katharinen, Germany. “I am proud to participate in MindGuard’s endeavor to prevent embolic stroke, accounting for most dismal cases with adverse clinical consequences,” said Prof. Sievert. “This first human implant is an important advancement towards preventing stroke and improving the quality of life of many patients.”

Mindguard’s founder, Dr. Ofer Yodfat, developed the novel approach behind the Diverter while working in the emergency room at Tel Hashomer Hospital in Tel Aviv six years ago. He decided that instead of trying to treat a stroke, which happens when there is a sudden interruption in the supply of blood to the brain, he would try to prevent the stroke from happening.

At present, the most common way to treat stroke patients is with anti-coagulant drugs which reduce the ability of the blood to clot, and therefore reduce the number of emboli being created. This method has been used for years, but David Gal, chairman of the board at MindGuard, says that a huge percentage of the population cannot take the drug because of side effects such as internal bleeding.

“The drugs reduce the ability of the body to fight any type of bleeding,” he told The Jerusalem Post.

Studies show that around 60% of the population at risk of stroke is not eligible to use these anti-coagulants, according to Gal. “That leaves you with a very large population that apart from taking aspirin regularly, cannot deal with the phenomenon,” says Gal.

The Diverter device is intended to reduce the occurrence of strokes in a different way — by diverting clots and thrombotic particles away from the brain into a non-hazardous location. The blood clots, known as cardio-emboli and thrombotic particles originating in the aorta and the large vessels, account for approximately 40% of all strokes with the most devastating consequences.

The simple catheter-based device is specifically designed for use in the carotid arteries, the vessels located on either side of the neck that serve as the main conduit for blood flow to the brain. Once implanted, the device, which is made of a self-expanding filter, acts like a traffic policeman for blood flow, diverting embolic material larger than 300 microns to safe areas, such as the large arteries that deliver blood to the face.

This minimally-invasive procedure is similar to the currently existing deployment of an endovascular stent, with very short procedural time and low complication rate.

“The device diverts the emboli before the blood flows to the brain,” says Gal. “It’s a preventative treatment. We are not treating a disease, but preventing the terrible outcome of several diseases from happening.”

MindGuard, which now employs 35 people, has carried out a series of extensive preclinical tests and has implanted more than 200 Diverter devices in pigs without any reported adverse events attributed to a disturbance of blood flow, according to the company.

It will start clinical trials on between 40-50 patients at three centers in Italy and two in Germany shortly. The company has already started selecting patients. These first trials are designed to prove the safety of the device. Once completed, MindGuard will receive a CE mark, enabling it to sell the device in Europe.

MindGuard expects to receive this validation around the end of next year. Once this is completed, the company will begin phase II clinical trials in Europe. These are very important if the device is to be recognized and reimbursed by European health authorities. Real sales are likely to begin only in 2005, once efficacy has been validated.

Parallel to this, the company will also begin clinical trials in the US – first to prove safety, and then later to prove efficacy in order to receive Food and Drug Administration (FDA) approval. Though MindGuard regards the US as its most important market, the company decided to start the regulatory path in Europe because the process is “somewhat easier” there, says Gal. “We will use some of the experience and data we got in Europe in the US trials,” he explains

Prof. Barry T. Katzen, the Medical Director at Miami Cardiac & Vascular Institute, said that this novel catheter-based approach “stands to make a major impact on healthcare resource utilization. For those patients who are candidates for the e-DIRECT procedure, there is currently no other treatment option. The prospect of an outpatient, elective procedure to reduce the lifetime risk of stroke for these patients means a significant reduction in cost of care.”

Yodfat founded MindGuard at the Naiot Technical Center incubator in 1998. The company is now located in Caesaria, north of Tel Aviv. In June, the company received funding from US medical giant Medtronic, a $7.6 billion company which sells medical products for people with chronic diseases in 120 countries around the world, and has some 29,000 employees. As part of the agreement, Medtronic will secure European distribution rights for MindGuard’s Diverter system.

“The completion of our financing round and the distribution agreement with Medtronic are both important milestones in MindGuard’s short history,” says Gal. “We expect that our strong cash position, coupled with strategic partnerships with our investors and Medtronic, will assist in the commercialization of our products and realization of the company’s innovative medical and technological vision.”